1. Field of the Invention
The present invention relates to a double containment manhole fitting for dual containment piping systems for fluids. In particular, the present invention relates to the dual containment manhole fitting which is an integral, one-piece unit allowing for simple and easy installation and allowing for ready accessibility to the inner carrier.
2. Prior Art
Double containment piping systems have become common in the chemical processing industries and others. A series of inner containment pipes are used to transport fluid therethrough. Concentric, outer containment pipes surround the inner containment pipes and contain and seal off any leakage from the carrier pipes. The containment pipe may also include drainage systems and leak detectors so that leaks from the carrier pipe may be attended to. In the past, when control of or access to the fluid within the inner carrier pipe was called for, a standard valve or cleanout fitting was installed in the carrier pipe line. Thereafter, a housing manhole or other box structure was constructed around the valve or cleanout fitting and around a break in the containment pipe. The structure would have a door or other access means for repair, service or control of the valve or cleanout fitting.
While this may achieve the intended purpose of leak containment, it does not comport with the leak detection systems in the containment pipe and may not be compatible with conventional hangers, anchors and pipe supports.
There exists a need for a one-piece integral dual containment manhole system which may be installed and connected to both the carrier pipes and containment pipes.
Accordingly, it is a principal object and purpose of the present invention to provide a one-piece integral dual containment manhole system for a double containment fluid system.
It is often required to be able to access the inner containment pipes which hold and transmit fluid through the double containment fluid system. A housing manhole or other box structure may be constructed around a break in the containment pipe and a port made in the carrier pipe. While these access points sometimes referred to as manhole fittings can be constructed, they do not provide a one-piece integral dual containment fitting which may be installed and connected to both carrier pipes and containment pipes.
It is, therefore, a principal object and purpose of the present invention to provide a one-piece integral dual containment manhole fitting allowing for ready access to an opening in the carrier.